Means for diverting energy from high-potential conductors



A. O. AUSTIN March 17, 1931.

MEANS FOR DIVERTING ENERGY FROM HIGH POTENTIAL CONDUCTORS Original Filed Sept. 8, 1928 /WLQ A TTOKNE Y Patented Mar. 17, 1931 UNITED STATES PATENT OFFICE ARTHUR 0. AUSTIN, OF NEAR BARBER-TON, OHIO, ASSIGN OR, BY MESNE ASSIGNMENTS, TO THE OHIO BRASS COMPANY, OF MANSFIELD, OHIO, A CORPORATION OF NEW JERSEY MEANS FOR DIVERTING ENERGY FROM HIGH-POTENTIAL COND'UGTORS flriginal application filed September 8, 1928, Serial No. 304,761.

September 16, 1929.

This invention relates to a construction which may be used in connection with a bushing insulator for diverting a relatively small amount of energyfrom a high potential conductor which passes through the insulator. The diverted current may be used for metering, relay operation, synchronizing or other purposes where it is not desired to employ an expensive potential transformer and where a comparatively small amount of energy is required.

@ne object of the invention is to provide an arrangement of the class named which shall he economical to manufacture, eflicient in operation, convenient to install, and which will not impair the insulation of devices in which it is used.

A further object is to provide means. for

@orrecting variations in current ratio and phase angle of the diverted current as relayed to the current in the main conductor.

Another object of the invention is to provide a device of the class named which shall be of improved construction and operation.

Other objects and advantages will appear from the following description. I

The invention is exemplified in the combination and arran ement of parts shown in the accompanying drawing and described in the following specification, and it is more particularly pointed out in the appended claims.

This is a division of application, Serial Number 304,762, filed September 8, 1928. v

The figure is an elevation with parts in section and parts diagrammatically shown illustrating one embodiment of the present invention. It is frequently desirable to equi high voltage bushings with current trans ormers for the operation of relays, metering, and

the indication of current flowing inithe cir cuit. Where the magnetic flux set -u in a current transformer of'this kind is ue to a single turn on the primary-side, the flux will be very weak and where the voltage on the conductor passing through the bushing is high, the diameter of the bushing must be large, thus requiring a magnetic core of very large diameter, Where the core Divided and this application filed Serial No. $93,001.

is placed outside the bushing. This tends to reduce the eficiency and accuracy of the current transformer and, hence, an improved type of current transformer for bushings is of the bushing. The secondary of the current transformer is made up of a number of turns located inside of the bushing shell. This arrangement makes a current transformer which can be used over quite a wide range of current in the primary and still provides an efi ective volt ampere capacity for the operation of connected equipment, such as relays, meters, etc. While the secondary winding may be connected to a transformer for stepping up or down, the ratio may be readily changed on the outside of the transformer. My prior patent shows means for efiecting material changes in the number of turns in the primary so that even though the current in the primary be small, an efi'ective transformer is provided.

Owing to the magnetizing component, the phase angle and ratio of the current transformer will vary much more than in transformers where the magnetic path is shorter. A

The present invention deals with an improved method of correcting these deficiencies in the current transformer in order that the ratio may be more accurate for metering or other purposes.

As the greatest difiiculty is encountered at very high voltages where the magnetic path in the current transformer, owing to It will be understood, however, that the principles ofthe present invention may be applied to other means for diverting energy from a highfpotential conductor.

Referring to the drawing as explained in my prior patent, the numeral 10 designates the lower section and the numeral 11 the upper section of a tubular conductor. The two sections being joined by a dielectric tube 12 to the ends of which the sections 10 and 11 are attached. A laminated soft iron core 13 is disposed within the tube 12 and the ends of the sections 10 and 11 are preferably swaged or shrunk onto the fibre sleeve 12 and .the core 13 so that together the parts 10, 11, 12, and 13 form a rigid, mechanical member.

A helical winding 14 is placed over the iron core 13'and insulating sleeve, and the ends of the winding are connected respectively to the conductors 10 and 11 so that the current in passing from one section to the other of the conductor can not flow in a straight line but must flow around and *magnetize the core 13. This' increases the magnetic flux in the iron core so that, al-

thought the current may be weak, the core will be sufliciently magnetized because of the plurality of turns. Insulating bafi'les 15 and 17 are disposed about the conductor formed of the tubes 10 and 11 and the I helix 14. A winding 18 surrounds the vbaflie 17 and forms the secondary winding of the current transformer. This secondary winding may have any suitable number of turns and may be placed as near the center ing 18. This greater diameter tends to cut down the intensity of the field outside of the bushing and thereby to improve the length and efliciency of the bushing and does not interfere 'with the efiicienoy of the current transformer, as in the case where the secondary of the current transformer must he slipped over the outside of the bushing. A metallized or charging surface 21 may be provided upon the outer surface of the bafile 17 which may be connected'to the conductor 18. This charging screen will relieve the winding 18 of any electrostatic stress so that it will not be. necessary to ground the winding '18. The

metallized surface or charging screen 21 should not form a short circuit turn in circling the bafile 17 since a short circuit turn in this position would. interfere with the operation of the winding 18.

It is evident that some of the magnetic in a path to includeall of the turns in the winding 18 but this will not materially imto some extent, by bafiles composed of magnetic material or of material having exceedingly low resistance, such as copper. By keeping the metal parts, such as the flange 22 of the bushing or the housing on which the bushing is mounted, at a considerable v distance from the axis of the bushing, a

large portion of the magnetic flux will return without cutting the short circuit turn formed by these metal parts. In order to assist in controlling the path of the magnetic flux, the baflie 17 may be wrapped with thin layers of iron as shown .at 23; the several layers being insulated from each other so'that a short circuit is not formed. This wrapping is placed outside of the winding 18. The wrapping projects well along the axis of. the bushing and will form a return path outside of the winding, 18 for a considerable portion of the magnetic flux emanating from the core 13. The magnetic wrapping 23 may be clamped or held to a ring 25, which, in turn, is su ported at the middle of the bushing by a p ate resting on the flange 22 but insulated therefrom. The ring 25 and wrapper 23 support the bafiies 15 and 17. A jumper 29 is connected to the lower section 10 of the center conductor and extends upwardly through the core 13 and up er section 11 of the tubular conductor an is connected at its upper end to one end of the spark gap 30. The gap terminals are insulated from each other and provided in the drawing. This provldes a gap for limiting the voltage across the winding 14' Y which will break down and relieve the insulation between the two ends of the sections 10 and 11 if abnormal stress is produced by transient disturbances or surges.

In the form of the invention shown in the drawing,-the current passing through the winding 14 excites the secondary winding 18 as explained in my prior patent. The ends of the secondary winding are connected to a transformer which supplies currentto the metering instrument or other translating device for which the current transformer is employed.

A supplemental winding 35 is connected at one-end to the conductor 10 and'atthe other endis connected to a lead 57 which is brought out through aninsulating sleeve 58 and connected 1: rough a series of condensers 65 to another conductor 66 of a 01 base system; Chargin current will flux set up by the helix 14 may not return yp a ow from the conductor 10 through the winding 35 and lead 57 to the condenser 65.

It will be apparent that the current flowing or increase the transformation ratio.

through the conductor 35 will be a function of the voltage and capacitance of the com denser in series with the lead 57 connected to the conductor 66. Since the current in the conductor 66 will have a different phase from that in the conductor 31, this current may be employed for counteracting the variation in phase angle and transformation ratio of the current in the secondary winding 18 by properly regulating the capacity of the condenser 65 and the number of turns in the winding 85. It will be apparent also that a supplemental correction may be introduced in the secondary circuit in the form of a corrective winding 60 provided in the transformer 28 and connected to the memhere 23, 21 and 18. The other end of the winding 28 is connected through variable resistance es and reactance 63 to ground for adjusting the effect of the corrective windin A spark gap 61 may be employed for limiting the voltage on the transformer winding 60*. The corrective winding 60 may, of course, be supplied with a current in the same manner as the corrective winding for the primary winding of the transformer; is, by a connection with another phase conductor.

It is evident that a transformer between the secondary of the current transformer and the meter, relay or synchronizing circuit is not necessary. /Vherea transformer is used, however, it is possible to cause the charging current to flow to ground through a transformer or other translating device, so that the pushing may be used as a coupling condenser in the manner disclosed in my prior patent 1,723,000..

ft is further evident that the corrective scheme has a wide application, particularly, where the correction is applied to the current transformer secondary circuit. W here a low voltage supply having the desired phase relation to the main circuit is obtained, by step-down transformers or other suitable means, it is possible to provide very effective correction for both phase angle and transformation ratio. With step-down transformers connected in Y or delta having suitable taps, it is possible to obtain a corrective current or potential of any phase angle desired. This makes it possible to change the phase angle and either reduce This correction may be made by a separate tap or winding in the secondary circuit of the current transformer or across a resistance or impedance in series with the secondary circuit.

If the current in the low voltage side of the power transformeris caused to flow through a series or current transformer, it is evident that the correction will increase with the current. This may be used in combination with a correction depending upon the voltage to maintain a more definite ratio and phase angle correction for a given range of current.

By properly connecting the secondaries of the current transformers in series with the current in the low voltage side of the transformers, practically any phase angle desired may be obtained for the correction vector. If a corrective current transformer having a relatively large number of ampere turns is used in the power circuit, the iron will become saturated and the correction will be relatively high for small currents, where it is usually most desired.

it claim: I

l. The combination with the conductors of a polyphase circuit, of a current transformer energized by one conductor of said circuit, and means energized by the current in another conductor, of said circuit for modifying the current in the secondary of said transformer.

2. The combination with a current transformer, of' a corrective winding for said transformer, and means for energizing said corrective winding comprising a conductor having current therein out of phase with the current in the primary of said current transformer.

3. The combination with the conductors of a polyphase circuit, of a current trans former energized by one of said conductors, and a corrective winding'for said current transformer connected with another conduc tor of said circuit.

4. The combination with the conductors of a polyphase circuit, of a current transformer energized by the current in one of said conductors, a corrective winding for said current transformer energized by the current of another of said conductors, and a condenser connected with said corrective winding.

5. The combination with the conductors of a polyphase circuit, of a current transformer energized by one of said windings, a corrective winding for said current transformer, and means for electrically connecting said corrective winding between conductors of different phases of said circuit.

6. The combination with the conductors of a polyphase circuit,-of a current trans former for diverting energy from one of said conductors, a corrective winding for said current transformer, and means for electrically connecting said corrective winding between conductors of different phases of said circuit, said means including a condenser.

7. The combination with the conductors of a polyphase circuit, of a bushing through which one of said conductors passes, a secondary winding forming a current transformer with the conductor in said bushing,

a correctivewinding for said current transformer, and means for connecting said corrective winding between said conductor and another conductor of said circuit.

5 8. The combination with a high potential conductor, of a tap energized by lines of force set up by said conductor for diverting energy from said conductor, a corrective circuit for said tap, and a second conductor having a current therein out of phase with said first named conductor for energizing said corrective circuit.

9. The combination with the conductors of a polyphase circuit, of a tap energized by the lines of force of one of said conductors for diverting energy from said conductor, and a correctivecircuit 'for said tap energizedby another of said conductors.- I 10. The combination with the conductors of a polyphase circuit, of a tap energized by lines of force set up by one of saidcon-Q ductors for diverting energy from said conductor, a corrective circuit for said tap connected' with another of said conductors, and 5 a condenser in said corrective circuit.

11. The combination with the conductors of a polyphase circuit, of a bushing in- V sulator for one of said conductors, a tap. insulated from said conductor by said bush ing insulator and energized by the lines of force set up by said conductor, a corrective v circuit for said tap, and means for connecting said corrective circuit with another conductor of said polyphase circuit. 12. The combination with the conductors of a polyphase circuit, of a bushing insulator for one of said conductors, a cur rent transformer for diverting energy from said conductors, said current transformer 40 being insulated by said bushing insulator,

and a corrective circuit for said bushing insulator energized by another conductor of said polyphase circuit.

13. The combination with a current 5 transformer, of a corrective winding for said transformer, and means for energizing saidcorrective winding comprising a con- -,ductor, and a source supplying voltage to said conductor out of phase with the voltage impressed on theprimary windingof said current transformer but having a definite phase relation therewith.

In testimony whereof I have signed my name to this specification this 14th day of September, A. D. 1929.

'ARTHUR O. AUSTIN.

CERTIFICATE or CORRECTION.

Patent No. 1,796,431. Granted March 17, 1931, to ARTHUR o. AUSTIN.

It is hereby certifiedthat error appears in the above numbered patent requiring correction as follows: In the heading to the printed specification, line 6, date of filing application, for the number "304,761" read 304,762; and that the Y said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 3rd day of November, A; D. 1931.

M. JQ Moore, (Seal) I ActingCommissioner of Patents.

DISCLAIMER 1,796,43L-Arthar 0. Austin, near Barberton, Ohio. MEANS FOR DIVERTING ENER Y FROM HIGH-POTENTIAL CONDUCTORS. Patent dated March 17, 1931. Disclalrner filed November 8, 1933, by the assignee, The Ohio Brass Company.

Hereby enters this disclaimer to that part of the claims in said specification which is in the following words, to wit:

2. The combination with a current transformer, of a corrective winding for said transformer, and means for energizing said corrective winding comprising a conductor having current therein out of phase with the current in the primary of said current transformer.

13. The combination with a current transformer, of a corrective Winding for [Oflicial Gazette December 5, 1.983.] 

